Control of Tourniquet Pain With an Axillary Ring of Subcutaneous Local Anesthetic

• Sponsor: University of North Carolina, Chapel Hill (Other)
• Overall Status: Completed
• CT.gov ID: NCT01829399
• Collaborator: (none)
• Enrollment: 24
• Location: 1
• Arms: 2
• Duration (Months): 9
• Patients Per Site Per Month: 2.7

Study Details

Study Description

Brief Summary

Purpose: Even with excellent regional anesthesia of the upper extremity, tourniquet (Tq) pain from an upper arm Tq can limit the ability to use regional anesthesia as the primary anesthetic for surgical procedures on the upper extremity. The aim of this study is to determine whether a subcutaneous ring of local anesthetic on the inner aspect of the upper arm just distal to axillary crease will significantly diminish Tq pain. If it does, peripheral nerve blocks distal to the Tq (i.e., nerve blocks at the elbow) could be used as the primary anesthetic for surgery of the hand and forearm. These distal peripheral nerve blocks have fewer complications than brachial plexus blocks performed at higher levels, and, postoperatively, the patient has better control of his or her arm when distal nerve blocks are used.

Procedures (methods): This is a prospective, cross-over study to examine the effectiveness of an upper arm Subcutaneous ring of local anesthetic alone in relieving Tq pain. This Subcutaneous ring of local anesthetic is often referred to as "Intercostobrachial nerve block" or "Subcutaneous ring anesthesia (SRA)." Twenty volunteers will be randomized into four groups of 5 participants each. During the initial experiment, the first group will be given SRA with 10-15 mL of 0.25% Bupivacaine with Epinephrine 1:200,000 on their dominant arm, the second group will be given SRA with 10-15 mL of 0.25% Bupivacaine with Epinephrine 1:200,000 on their non-dominant arm, the third group will be given "sham" SRA with saline on their dominant arm, and the fourth group will be given "sham" SRA with saline on their non-dominant arm. 15 minutes after SRA, a Tq will be applied to the arm with the subcutaneous injection and it will be inflated to 100 mm Hg above the subject's baseline systolic blood pressure. We will monitor heart rate, blood pressure (opposite arm) and pain (0 to 10 VAS) every 5 minutes. Each Tq will be released when the subject requests deflation or when 1 hour of Tq time has elapsed, whichever occurs first. The subject's discomfort level (VAS) just prior to deflation will be recorded. Since Tq pressure alone can inhibit nerve function, we will monitor motor and sensory function distal to the Tq every 10 minutes during Tq inflation and for 30 minutes after Tq deflation. One to two weeks after this initial study, the same 20 subjects will receive SRA on the same arm and the same parameters will be measured. The 10 subjects who received 0.25% Bupivacaine the first time will receive Normal Saline, and the 10 subjects who received Normal Saline the first time will receive 0.25% Bupivacaine. In this way, each subject will act as his or her own control.

Condition or Disease	Intervention/Treatment	Phase
Application Site Discomfort; Medical Device Discomfort	Drug: Bupivacaine with Epinephrine; Drug: Normal Saline	Phase 4

Study Design

• Study Type: Interventional
• Actual Enrollment: 24 participants
• Allocation: Randomized
• Intervention Model: Crossover Assignment
• Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
• Primary Purpose: Prevention
• Official Title: Control of Tourniquet Pain With an Axillary Ring of Subcutaneous Local Anesthetic
• Study Start Date: Apr 1, 2013
• Actual Primary Completion Date: Jan 1, 2014
• Actual Study Completion Date: Jan 1, 2014

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Injected with Bupivacaine A subcutaneous axillary ring of 10 to 15 mL of 0.25% Bupivacaine with epinephrine 1:200,000 will be injected in the arm 15 minutes prior to tourniquet inflation.	Drug: Bupivacaine with Epinephrine; 10-15 mL 0.25% Bupivicaine with epinephrine 1:200,000 subcutaneous axillary ring; Other Names: Marcaine, Exparel, Sensorcaine
Sham Comparator: Injected with saline A subcutaneous axillary ring of 10 to 15 mL of normal saline will be injected in the arm 15 minutes prior to tourniquet inflation.	Drug: Normal Saline; Other Names: Placebo

Outcome Measures

Primary Outcome Measures

1. Time in Minutes That Tq Remained Inflated [Tq was inflated 15 minutes after injection of Bupivacaine or placebo and remained inflated until subject could no longer tolerate it. Maximum allowable inflation time per session was 60 minutes.]

   15 minutes after either Bupivacaine or placebo injection, Tq was inflated to 100 mm Hg over subjects systolic blood pressure. When the subject found the Tq too uncomfortable, the Tq was deflated and the time documented. Approximately one month later, each subject had the opposite injection of either placebo or Bupivacaine on the same arm, and the duration of Tq inflation was again measured. Due to a strong crossover effect, only the data assessed from the first intervention was analyzed.

Secondary Outcome Measures

1. Pain Score at Time of Tq Deflation [Tq will be deflated upon subject's request. VAS is assessed at time of deflation for degree of discomfort prompting deflation request, up to 60 minutes post intervention.]

   A visual analog pain score (VAS) from 0 to 10 was assessed at the time of Tq deflation. 0 indicating no pain, and 10 indicating the worst possible pain. All participants requested deflation prior to the maximum allowable 60 minutes, Subjects were instructed to request deflation at the same degree of discomfort for each visit. Due to a strong crossover effect, only the data assessed from the first intervention was analyzed.

Eligibility Criteria

Criteria

• Ages Eligible for Study: 18 Years to 70 Years
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: Yes

Inclusion Criteria: Volunteers will be eligible for the study if they meet all of the below criteria;

• American Society of Anesthesiologists (ASA) classification I or II

• 18 years of age to a maximum of 70 years of age

Exclusion criteria:

• Pre-existing parasthesia or neuropathy of any kind

• History of excessive alcohol consumption (> three drinks per night)

• Take analgesics on a regular basis

• History of any drug abuse

• Baseline systolic blood pressure ≥ 150

• Baseline diastolic blood pressure ≥ 85

• BMI ≥ 30 Pregnancy Allergic reaction to local anesthetic

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	University of North Carolina at Chapel Hill Medical Center	Chapel Hill	North Carolina	United States	27599

Sponsors and Collaborators

• University of North Carolina, Chapel Hill

Investigators

• Principal Investigator: Randall F Coombs, M.D., University of NC at Chapel Hill Dept. of Anesthesiology

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.

• Responsible Party: University of North Carolina, Chapel Hill
• ClinicalTrials.gov Identifier: NCT01829399
• Other Study ID Numbers: 12-2373
• First Posted: Apr 11, 2013
• Last Update Posted: Oct 22, 2015
• Last Verified: Oct 1, 2015

• Keywords provided by University of North Carolina, Chapel Hill: Tourniquet pain; Subcutaneous axillary local anesthetic; ability to tolerate tourniquet discomfort.
• Additional relevant MeSH terms: Epinephrine; Bupivacaine

Study Results

Participant Flow

Arm/Group Title	Bupivacaine Ring 1st Visit, Saline Ring 2nd Visit	Saline Ring 1st Visit, Bupivacaine Ring 2nd Visit
Arm/Group Description	Participants received a subcutaneous axillary ring injection with 0.25% Bupivacaine with epinephrine 1:200.000 on the first visit and a subcutaneous axillary ring injection with saline on the second visit.	Participants received a subcutaneous axillary ring injection with normal saline on the first visit and a subcutaneous axillary ring injection with 0.25% Bupivacaine with epinephrine 1:200.000 on the second visit.
Period Title: Visit 1
STARTED	12	12
COMPLETED	12	12
NOT COMPLETED	0	0
Period Title: Visit 1
STARTED	12	12
COMPLETED	12	12
NOT COMPLETED	0	0

Baseline Characteristics

Arm/Group Title	Bupivacaine Ring 1st Visit, Saline Ring 2nd Visit	Saline Ring 1st Visit, Bupivacaine Ring 2nd Visit	Total
Arm/Group Description	On the first visit, subcutaneous axillary ring of 10 to 15 ml of 0.25% Bupivacaine with epinephrine 1:200,000 was injected 15 minutes prior to tourniquet inflation. On the second visit, a subcutaneous axillary ring of 10 to 15 ml of saline was injected 15 minutes prior to tourniquet inflation.	On the first visit, a subcutaneous axillary ring of 10 to 15 mL of normal saline was injected 15 minutes prior to tourniquet inflation. On the second visit, a subcutaneous axillary ring of 10 to 15 ml of 0.25% Bupivacaine with epinephrine 1:200,000 was injected 15 minutes prior to tourniquet inflation.	Total of all reporting groups
Overall Participants	12	12	24
Age (Count of Participants)
<=18 years	0 0%	0 0%	0 0%
Between 18 and 65 years	12 100%	12 100%	24 100%
>=65 years	0 0%	0 0%	0 0%
Age (years) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [years]	31.7 (10.0)	32.3 (10.5)	32.0 (10.3)
Sex: Female, Male (Count of Participants)
Female	6 50%	6 50%	12 50%
Male	6 50%	6 50%	12 50%
Region of Enrollment (participants) [Number]
United States	12 100%	12 100%	24 100%
Arm Dominance (participants) [Number]
Dominant Arm	6 50%	6 50%	12 50%
Non-Dominant Arm	6 50%	6 50%	12 50%

Outcome Measures

1. Primary Outcome

Title	Time in Minutes That Tq Remained Inflated
Description	15 minutes after either Bupivacaine or placebo injection, Tq was inflated to 100 mm Hg over subjects systolic blood pressure. When the subject found the Tq too uncomfortable, the Tq was deflated and the time documented. Approximately one month later, each subject had the opposite injection of either placebo or Bupivacaine on the same arm, and the duration of Tq inflation was again measured. Due to a strong crossover effect, only the data assessed from the first intervention was analyzed.
Time Frame	Tq was inflated 15 minutes after injection of Bupivacaine or placebo and remained inflated until subject could no longer tolerate it. Maximum allowable inflation time per session was 60 minutes.

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Bupivacaine Axillary Ring on 1st Visit	Saline Axillary Ring on 1st Visit (Control Group)
Arm/Group Description	Participants received a subcutaneous axillary ring injection with 0.25% Bupivacaine with epinephrine 1:200.000.	Participants received a subcutaneous axillary ring injection with normal saline.
Measure Participants	12	12
Mean (95% Confidence Interval) [Minutes]	30.5	22.4

2. Secondary Outcome

Title	Pain Score at Time of Tq Deflation
Description	A visual analog pain score (VAS) from 0 to 10 was assessed at the time of Tq deflation. 0 indicating no pain, and 10 indicating the worst possible pain. All participants requested deflation prior to the maximum allowable 60 minutes, Subjects were instructed to request deflation at the same degree of discomfort for each visit. Due to a strong crossover effect, only the data assessed from the first intervention was analyzed.
Time Frame	Tq will be deflated upon subject's request. VAS is assessed at time of deflation for degree of discomfort prompting deflation request, up to 60 minutes post intervention.

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Bupivacaine Ring 1st Visit	Saline Axillary Ring on 1st Visit (Control Group)
Arm/Group Description	On the first visit, a subcutaneous axillary ring of 10 to 15 mL of 0.25% Bupivacaine with epinephrine 1:200,000 was injected 15 minutes prior to tourniquet inflation.	On the first visit, a subcutaneous axillary ring of 10 to 15 mL of normal saline was injected 15 minutes prior to tourniquet inflation.
Measure Participants	12	12
Mean (95% Confidence Interval) [scores on a scale]	6.1	5.0

Adverse Events

Arm/Group Title	Bupivacaine Axillary Ring		Saline Axillary Ring (Control Group)
Arm/Group Description	Participants received a subcutaneous axillary ring injection with 0.25% Bupivacaine with epinephrine 1:200.000		Participants received a subcutaneous axillary ring injection with normal saline
All Cause Mortality
	Bupivacaine Axillary Ring		Saline Axillary Ring (Control Group)
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	/ (NaN)		/ (NaN)
Serious Adverse Events
	Bupivacaine Axillary Ring		Saline Axillary Ring (Control Group)
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/12 (0%)		0/12 (0%)
Other (Not Including Serious) Adverse Events
	Bupivacaine Axillary Ring		Saline Axillary Ring (Control Group)
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/12 (0%)		0/12 (0%)

Limitations/Caveats

Originally this was designed as a crossover study. However, there was a very strong crossover effect which invalidated the results from the second series of injections. Therefore, we have only analyzed the data from the first visit.

More Information

Certain Agreements

All Principal Investigators ARE employed by the organization sponsoring the study.

There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.